1. Field
This disclosure relates generally to circuits, and more specifically, to a voltage sampling switch circuit and method therefor.
2. Related Art
Board level system developers are increasingly challenged as semiconductor process technology advances for modern integrated circuits (ICs). For example, a system may include multiple ICs assembled on a common printed circuit board (PCB). The multiple ICs are likely to be sourced from different manufacturers and processed in various process technologies. Operating voltages supplied to the multiple ICs are generally based on the process technology of each IC and reflected in the manufacturer's specifications. For example, one IC may require 5.0 volts to operate, while another IC may require 3.6 volts to operate, and so on. The system PCB design typically includes electrical traces which route appropriate supply voltages to each IC.
System manufacturers may qualify a particular PCB design having a corresponding set of ICs, and continue to use the PCB design and set of ICs for several years for a given product or family of products. Advances in process technology enable smaller transistor features which may in turn allow for one or more ICs in the set to realize cost reductions. However, smaller transistor usually require a lower operating voltage. For the system manufacturers to gain advantages by replacing an IC with a lower cost IC manufactured at a more advanced process technology, a new system PCB design could be required to route the appropriate lower voltage to the lower cost IC. Design changes to the PCB would likely require a requalification of the system, impacting production and incurring significant costs. As such, there is a need for ICs to be processed in an advanced technology without impacting the supply voltage requirements of the ICs.